Floor box



Dec. 23,1969

C. T. F'LACHBARTH" FLOORBOX} Filed Aug. 7. i967 United States PatentU.S. Cl. 174-51 3 Claims ABSTRACT OF THE DISCLOSURE Floor box havingconduit connector sections to receive maximum size conduit or withadaptor to receive smaller size conduit and also having receptaclesupport adjustable without twisting wires.

This invention relates to under floor distribution systems and inparticular relates to an improved floor box for use in such systems.

One of the principal objects of the invention is to provide a singlefloor box which is constructed and provided with means which adapt thesingle box for use with all of the various different size conduitscommonly employed in under floor systems and thereby eliminate the needfor a vast inventory of floor boxes as now is the case.

Another principal object of the invention is to provide a floor boxhaving means supporting a receptacle for vertical adjustment toaccommodate varying floor levels without twistig the wires connected tothe receptacle.

The invention will be explained below in connection with the followingdrawings wherein:

FIGURE 1 is a perspective view of a floor box constructed in accordancewith the invention;

FIGURE 2 is an enlarged plan view of the floor box of FIGURE 1 withcertain parts broken away;

FIGURE 3 is an elevational view taken along the lines of 33 of FIGURE 2.

FIGURE 3a is a fragmentary view taken along the lines 3a-3a of FIGURE 2;

FIGURE 4 is an end view showing the manner in which an under floorconduit of maximum size is connected to the floor box;

FIGURE 5 is a perspective view of an adaptor used with the floor box toadapt the same for smaller sized conduits;

FIGURE 6 is an end view showing the manner in which an adaptor is usedto support smaller size conduits for connection to the floor box.

The floor box shown in FIGURE 1 is of two-piece construction there beingan upper section generally designated by numeral 1 and a lower sectiongenerally designated by numeral 2. The sections abut one another along ahorizontal plane and are fastened securely by the screws 3. Thelevelling devices 4 provide for levelling and adjusting the boxvertically at installation. The box has connector sections 5, 6, 7 and 8for joining tubular under floor conduits. For installation and non-usepur poses the box has a cover 10 secured to the top of the box by thescrews 11. The cover is replaced by a floor fitting when a receptacle isinstalled in the box.

The interior of the box i hollow and the design provides for an insidecontour which is relatively clean or without burrs and is funnel-like inorder to assist the pulling of wires through the same withoutdifliculty. For example, with reference to FIGURES 2 and 3 it will benoted that the structure of the box (adjacent connector section 5)contemplates two vertically extending walls 12 and 13 which are angledwith respect to the connector section and top and bottom walls 14 and 15which are also angled with respect to the connector section. Theseangled walls are terminated generally by an abutment 16 which is roundand smooth. It will be apparent there- Patented Dec. 23, 1969 fore thatwires can be pulled through the connector 5 toward the top of the box ortoward the left and right hand sides and that the smooth abutment andthe shape of the walls will promote movement of the wires. The otherconnector sections have similar structure.

Heretofore it has been generally the practice to provide single purposefloor boxes, i.e., with connector sections specifically designed for oneparticular size conduit and in some instances with connector sectionsspecifically designed for conduits of two different sizes. This systemof single purpose boxes has the undesirable characteristic of beinginflexible and necessitates a vast inventory of floor boxes which notonly adds to manufacturing costs but takes up space and creates aproblem of identification.

The present invention eliminates the foregoing disadvantages byproviding a single box having connector sections of identicalconstruction and each being arranged to receive the maximum size conduitand also arranged to receive adaptors which permit the connector sectionto accommodate conduits of smaller size. Thus a single box with a fewadaptors supplants a wide variety of single purpose boxes.

With reference to FIGURES 1 and 4 it will be seen that the connectorsection 7 has a partially circular sur-v face 20. The surface subtendsan angle of 270 terminating at the ends 21 and 22. A wall 23 has anouter periphery 24 which is partially circular and is joined to thesurface 20 at the ends 21 and 22. Inwardly of the wall 23 are planarsurfaces 25 and 26 which intersect one another and respectively join theends 21 and 22 of the surface 20. The surfaces 20 and 24 and the walls25 and 26 form a passage which is open to the interior of the box, theterminal point of the passage being the abutment 16.

The surface 20 and the surface 24 form a circular surface dimensioned tomake a snug fit with the outer surface of the maximum size tubularconduit which is to be connected to the box. As shown the conduit isdesignated by the number 30. Preferably the conduit 30 engages theabutment 16.

The conduit 30 is held in the connector and is electrically groundedwith respect to the box by means of a screw which is arranged not onlyto contact the maximum size conduit but also to contact smaller sizedconduits (as is explained later).

As shown the grounding screw 31 is threaded into an aperture 32 in thebox, the projection of the axis A of which forms a chord with thesurface 20 as is indicated in FIGURE 4.

Each connector section is arranged to receive adaptor which will providefor a smaller sized conduit to be connected to the box. The manner inwhich this is done is noted below.

With reference to FIGURES 1 and 4 it will be observed that the wall 23and planar surfaces 24 and 25 form a small pocket. In the embodimentshown the abutment 16 also forms part of the pocket. The purpose of thispocket is to maintain an adaptor within the passage particularly duringthe time when the tubular conduit is being connected.

A preferred form of adaptor is shown in FIGURE 5 and comprises a pair ofplanar surfaces 33 and 34 together with an extension 35 having partiallycircular surface 36. The adaptor is put into the connector section inthe manner that is shown in FIGURE 6; i.e. with the planar surfaces 33and 34 respectively engaging the planar surfaces 25 and 26 and the walls40 and 41 of the adaptor being respectively held between the abutment 16and the wall 23.

The surface 36 on the adaptor faces the surface 20 and is dimensioned toaccept and make a snug fit of the surface 20.

"duits of the various standard sizes for example /2", A,

1-""and 1%" diameter. With the above described construction a single boxequipped With an appropriatesize adaptor adapts'the box for'use with allthe various size conduits and the box can be set up for u'sewithconduits of all one size or use with conduits of different sizes. i I

"Another feature of the invention is in the'meanssupporting thereceptacle for vertical adjustment Without twisting the wires connectedto the receptacle.

As seen in FIGURE 3 the top section 1 has an aperture 43 threaded as at44. Just below the threaded section 44 are a pair of diametricallyopposed tabs (FIGURES 2 and 3a) 45 and 46 which have threaded holes (see45a). A bushing 50 disposed in the aperture has threads 51 mating withthreads 44 providing for the bushing to be adjustable vertically in theaperture. The bushing carries a receptacle R, the mounting arms 52 and53 of which carry the screws 54 and 55 which pass through holes in thebushing, one of such holes being shown at 60 in FIG- URE 3a.

The installation of the receptacle and the vertical adjustment featureare explained following.

Assuming that the floor box is installed with the cover in place and itis desired to put in a floor receptacle and bell-type floor fitting (notshown). First the cover 10 is removed and the bushing 50 is threaded inthe aperture 34 until the shoulder 62 is flush with the floor tile. Thewires inside the box are then fished up and connected to the receptacle.The bushing then is turned so that the holes in the bushing line up withthe threaded holes in the tabs. The screws 54 and 55 are then put intoplace and the receptacle locked down.

With the above construction it will be noted that the receptacle andbushing mounting holes can be lined up with the threaded holes in thetabs by turning the bushing less than 90. This 90 or less turn moves thebushing only a very short distance axially because of the pitch on thethreads and therefore the level of the bushing with the floor surface isnot disturbed.

Before closing it is pointed out that connector sections that are notjoined with an under floor conduit can be blocked off as by plugs whichare inserted in the passage way and locked down by the grounding screws,for example note the plugs 62 in the connector section 5.

I claim:

1. A hollow floor box having a plurality of connector sections forjoining under floor tubular conduits to the box, each connector sectionbeing constructed by means forming:

a partially circular surface and a pair of intersecting planar surfacesrespectively joining the ends of said partially circular surface, thepartially circular and planar surfaces forming a passage open to theinterior of the box to receive alternatively a tubular conduit ofmaximum size or an adapter carrying a tubular conduit of smaller size,the partially circular surface being dimensioned to accept and make asnug fit with the outer surface of the maximum size tubular conduit tobe connected to the box and the planar surfaces being for use insupporting an adapter and smaller size conduit in the passage;

a threaded aperture open to said passage, the projection of the axis ofthe passage forming a chord with said partially circular surface; and

a grounding screw in said aperture adapted to engage a tubular conduitof maximum size in said passage and also a tubular conduit of smallersize supported :by an adapter in said passage.

2. A hollow floor box having a plurality of connector sections for"joining under "H001" tubular C'O'ndllit's' "f6 the box, each connectorsection being constructed by means forming:

a partially circular surface;

a wall, the outer periphery of which is partially circular and is joinedto the ends of first said partially circular surface, the two-partiallycircular surfaces forming acomplete circular surface and a pair ,of ..ir1tersecting planar surfaces disposed inwardly of said wall andrespectively joining the ends of first said partially circular surfaces,the partially circular and planar surfaces forming a passage open to theinterior of the box to receive alternatively a tubular conduit ofmaximum size or an adapter carrying a tubular conduit of smaller size,the circular surface being dimensioned to accept and make a snug fitwith the outer surface of the maximum size of tubular conduit to beconnected to the box and said wall and said planar surfaces forming apocket for supporting adapter and smaller'size conduit in the passage; athreaded aperture open to said passage, the projection of the axis ofthe passage forming a chord with first said partially circular surface,the chord being spaced from the radius center of said particallycircular surfaces; 1

a grounding screw in said aperture adaptedto engage a tubular conduit ofmaximum size in said passage and also a tubular conduit of smaller sizesupported by an adapter in said passage; and

abutment means disposed at the inner end of said passage to be engagedby atubular-conduit insaid passage and by an adapter in said pocket. 3.A hollow floor box having a plurality of connector sections for joiningunder floor tubular conduits to the box, each connector section beingconstructed by means forming:

apartially circular surface; a wall, the outer periphery of which ispartially circular and is joined to the ends of first said partiallycircular surface, the two partially circular surfaces forming a completecircular surface and a pair of intersecting planar surfaces disposedinwardly of said wall and respectively joining the ends of first saidpartially circular surface, the partially circular and planar surfacesforming a passage open to the interior of the box to receivealternatively a tubular conduit of maximum size or an adapter carrying atubular conduit of smaller size, the circular surface being dimensionedto accept and make a snug fit with the outer surface of the maximum sizetubular conduit to be connected to the box and said wall and said planarsurfaces'forming a pocket; an adapater in said pocket, the adapter beingforuse in supporting a tubular conduit of lesser diameter than theconduit of maximum diameter and the adapter having means forming a pairof planar surfaces in engagement with first said planar'surfac'es, theengagement of the planar surfaces preventing the adapter from rotatingand also positioning the adapter in the passage and an extension havinga partially circular surface facing a portion of first said partiallycircular surface and being dimensioned to accept and make a snug fitwith a tubular conduit of lesser diameter than the said maximum so thatthe lesser diameter conduit also engages a portion of first saidpartially circular surface; I

a threaded aperture open to said passage, the projection of the axis ofthe passage forming a chord with first said partially circular surfaceand the chord being spaced from the radius center of first saidpartially circular surface; and

a grounding screw in said aperture adapted to engage a tubular conduitof maximum size or alternatively 3,435,933 5 6 the tubular conduit oflesser size when the same is LEWIS H. MYERS, Primary Examiner d b dSupporte y sald a apter D. A. TONE, Assistant Examiner References CitedUNITED STATES PATENTS 5 1,271,473 7/1913 Krantz 174--s3 X 174- 57, 65;285-177, 173, 404 1,880,107 9/1932 Roseman 285-177 X 2,316,835 4/1943Blood 174-525

